Silicon photonics is the application of photonic systems which use silicon as an optical medium. The silicon is usually patterned with sub-micrometer precision, into microphotonic components. Silicon photonic devices can be made using existing semiconductor fabrication techniques, and because silicon is already used as the substrate for most integrated circuits, it is possible to create hybrid devices in which the optical and electronic components are integrated onto a single microchip. Silicon photonics include silicon waveguides which, due to their unique guiding properties, can be used for communications, interconnects, biosensors, etc.
Monolithic integration of silicon photonics is required for next generation terrabit communications and highly integrated, dense structures. Currently, the interconnects in such structures are copper. However, copper is at inflexion point in that moving to higher gigabyte performance, e.g., 25 gigabytes and above, involves additional costs and power consumption. This creates demand for silicon photonics technology to transfer data.